Billiards are leisure sports played on a billiards table to score points by hitting red and white balls using a cue stick. Billiards are generally categorized as four-ball billiards, carom billiards, pool, and the like. Four-ball billiards is played using two red balls and two white balls, while carom billiards is played using a single red ball and two white balls.
According to the terms used in billiards, a ball hit with a cue stick by a player is referred to as a “cue ball,” a first ball contacted by the cue ball is referred to as a “first object ball,” and a second ball contacted by the cue ball is referred to as a “second object ball.”
Billiards requires a process of delivering a cue ball to hit a predetermined point of a first object ball. Here, hitting the predetermined point of the first object ball with the cue requires aiming the cue ball such that a portion of the cue ball overlaps a predetermined portion of the object ball. The overlapping portions may be referred to as ½, ⅓, ¼, ⅕, ⅙, etc. These numbers also indicate portions of the diameter of the object ball relevant to points on the object ball contacted by the cue ball.
When playing a billiard game or practicing billiards, a cue ball is hit with a cue stick to contact a predetermined point on a first object ball. Here, it is necessary to aim the tip of the cue stick at a specific point. However, the point, to which the tip of the cue stick is to be directed, may be obscured and is unfixed, and thus, it may be difficult for a novice to aim.
That is, although billiard experts advise novices to perform the aiming on the basis of conceptual and numerical bases, it is impossible to determine a point of the object ball on which the tip of the cue stick is to be aimed. When delivering a cue ball to an object ball, it is essentially important to accurately aim the cue ball to hit an intended point on the object ball in order to improve billiard skills. Regardless of such necessity, no related-art solutions, by which aiming at an intended point on the object ball can be trained, have been found.
In this regard, Korean Utility Mode Application Publication No. 20-2011-0003785 disclosed “BILLIARD BALL COURSE TRAINING TOOL.” According to this document, a training tool provided with an object ball (e.g. a first object ball) is placed on a predetermined location of a billiard table. In this position, a cue ball (or impact ball) is hit with a cue stick to be delivered to the object ball (or a target ball). After contacting the object ball, the cue ball moves around the table. In this manner, a trainee can train to deliver the cue ball along an intended course on the table.
Accordingly there has been demand for the development of a new solution, by which a person can easily practice aiming the cue ball at the object ball, such that a portion of the cue ball overlaps a portion of the object ball, in order to improve his or her billiard skills.